Ports of Auckland has withdrawn a lockout notice previously issued to more than 300 striking union members.
The company is in an industrial dispute with the Maritime Union over a collective contract. Four days of disruption at the port ended on Monday night and more due to start on Thursday.
On Tuesday, Maersk Shipping moved one of its shipping services from Auckland to the Port of Tauranga.
Ports of Auckland is now challenging the union to withdraw its strike notice.
Chief executive Tony Gibson told Nine to Noon that mediation was due to start on Friday, but the company will not meet the union while they are striking.
Importers and exporters are urging both parties to resolve the dispute.
But the Importers Institute says both parties need to come to an agreement before the dispute becomes catastrophic for businesses.
Secretary Daniel Silva says some companies are still waiting for perishable goods and they might not be able to sell them at all if they don't get them by Christmas.
The New Zealand Shippers Council, which represents companies such as Fonterra, says goods are only being delayed one to two days at the moment.
But chairman, Greg Steed says there could be a delay of up to four days if the more strikes occur.
The Maritime Union on Wednesday issued notice of another strike on 23 December. It is the third strike notice issued by the union.